Where is the 02 sensor heater circuit bank 1 located on a 2000 Dodge Durango located?

The exact location of the O2 sensor heater circuit for Bank 1 on a 2000 Dodge Durango will depend slightly on the engine (3.9L, 4.7L, or 5.9L). There isn't a single, universally labeled "O2 sensor heater circuit bank 1" location. The heater is *part* of the upstream O2 sensor itself.

To find it:

1. Identify Bank 1: Bank 1 is generally the side of the engine where cylinder #1 is located. Consult your owner's manual or a repair manual specific to your Durango's engine for the cylinder numbering.

2. Locate the Upstream O2 Sensor (Bank 1): This sensor is located in the exhaust manifold or the exhaust pipe very close to the manifold, *before* the catalytic converter on Bank 1. It's usually a threaded sensor that screws into the exhaust.

3. The Heater is Integrated: The heater element is *inside* the O2 sensor itself. You won't see a separate heater circuit component. The wiring for the heater circuit will run from the sensor to the engine control module (ECM). You might be able to trace the wires back to the ECM, but it's difficult to pinpoint without a wiring diagram.

In short: You won't find a separate "heater circuit" – it's within the upstream O2 sensor on Bank 1. Finding the sensor is the key. Use a repair manual specific to your Durango's year and engine for a precise location diagram.